A new study published in the medical journal Neurology suggests that impaired kidney function is a risk factor for cognitive decline in old age. The study, conducted by researchers at Rush University Medical Center, found that poor kidney function was linked specifically with cognition related to memory functions. Damage to one of these functions, episodic memory, which retrieves memories of time, place, associated emotions and other contextual knowledge, is often the earliest sign of Alzheimer's disease.

"Given the dearth of modifiable risk factors for age-related cognitive decline, these results have important public health implications," said Dr. Aron Buchman, a neuroscientist in the Rush Alzheimer's Disease Center.